/*
 *  compression/DecompressorLHA.cpp
 *
 *  Copyright 2009 Peter Barth
 *
 *  This file is part of Milkytracker.
 *
 *  Milkytracker is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  Milkytracker is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with Milkytracker.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

/*
 *  DecompressorLHA.cpp
 *  milkytracker_universal
 *
 *  Created by Peter Barth on 22.06.08.
 *
 */

#include "DecompressorLHA.h"
#include "XMFile.h"
#include "XModule.h"
#include "unlha32.h"

// -- LHA --------------------------------------------------------------------
class XMFileStreamer : public CLhaArchive::StreamerBase
{
    private:
        XMFile& f;

        pp_uint32 currentPos;
    protected:
        virtual pp_uint8 get(pp_uint32 pos)
        {
            pp_uint8 result;
            if (currentPos != pos)
            {
                f.seek(pos);
                result = f.readByte();
                currentPos = f.pos();
            }
            else
            {
                result = f.readByte();
                currentPos = f.pos();
            }

            return result;
        }
    public:
        XMFileStreamer (XMFile& f) :
            f(f)
        {
            currentPos = f.pos();
        }

        virtual void read(void* buffer, pp_uint32 from, pp_uint32 len)
        {
            if (currentPos != from)
            {
                f.seek(from);
                f.read(buffer, 1, len);
                currentPos = f.pos();
            }
            else
            {
                f.read(buffer, 1, len);
                currentPos = f.pos();
            }
        }
};

struct ModuleIdentifyNotifier : public CLhaArchive::IDNotifier
{
    virtual bool identify(void* buffer, pp_uint32 len) const
    {
        mp_ubyte buff[XModule::IdentificationBufferSize];
        memset(buff, 0, sizeof(buff));
        memcpy(buff, buffer, len > sizeof(buff) ? sizeof(buff) : len);

        return XModule::identifyModule(buff) != NULL;
    }
};

DecompressorLHA::DecompressorLHA (const PPSystemString& filename) :
    DecompressorBase(filename)
{
}

bool DecompressorLHA::identify(XMFile& f)
{
    f.seek(0);

    XMFileStreamer streamer(f);

    CLhaArchive archive(streamer, f.size(), NULL);

    bool res = archive.IsArchive() != 0;

    return res;
}

const PPSimpleVector<Descriptor>& DecompressorLHA::getDescriptors(Hints hint) const
{
    descriptors.clear();
    descriptors.add(new Descriptor("lha", "LHA Archive"));
    return descriptors;
}

bool DecompressorLHA::decompress(const PPSystemString& outFilename, Hints hint)
{
    XMFile f(fileName);

    if (!f.isOpen())
        return false;

    XMFileStreamer streamer(f);

    ModuleIdentifyNotifier idnotifier;

    CLhaArchive archive(streamer, f.size(), &idnotifier);

    if (!archive.IsArchive())
        return false;

    pp_uint32 result = archive.ExtractFile();

    if (result && archive.GetOutputFile())
    {
        const char* id = XModule::identifyModule(archive.GetOutputFile());
        if (id)
        {
            XMFile outFile(outFilename, true);
            if (!outFile.isOpenForWriting())
                return false;

            outFile.write(archive.GetOutputFile(), 1, archive.GetOutputFileLength());
            return true;
        }
    }

    return false;
}

DecompressorBase* DecompressorLHA::clone()
{
    return new DecompressorLHA(fileName);
}

static Decompressor::RegisterDecompressor<DecompressorLHA>registerDecompressor;